Steel alloy



ticles, that is to say articles which. in service and valve PatentedJuly 7, lglzfi.

eaten.

DAVE 0'. GILES, 0F LATRGBE, PENNSYLVANIA.

s'rnnr. ALLOY.

Ho Drawing.

I To all whom it mag emocrat Be it known that l, DAVID J. GILES, a citizen of the United States, and a resident of Latrobe, in the countyofWestmoreland and State of Pennsylvania, have invented a new and usefulImprovement in Steel Alloys, of which the following is a specification.

The object of this invention is to provide a readily forgeable andotherwise workable steel alloy which may be economically manufacturedand which, although unlimited to any particular use or uses, ispeculiarly suitable for the manufacture of hot work arare subjected torepeated heating.

The steel alloy provided according to the invention includes tungsten ormolybdenum, cobalt, chromium and carbon. It preferably contains noadditional alloying elements except those that may be present asimpurities. The amounts of these elements present in the alloy are fromabout 2.0 to 7.0% tungsten or molybdenum, preferablythe former, .2 to5.0% cobalt, 2.0 to 8.0% chromium, and .2 to 1.5% carbon.v Silicon mayalso be added upto about 3.0%. The

several elements entering into the alloy may be present within about theranges stated, although the preferred alloy contains about 0.0%oftungsten or molybdenum, 5% cobalt, 7.0% chromium, 0.8% silicon and l5%carbon. I

From an alloy of this preferred analysis there were manufactured valves,valveseats leeves for internal combustion engines which were subjectedto severe tests and found to be much superior to the same partsmanufactured from the best known prior commercial alloy used for thepurpose. The standard test which is given to internal combustion enginevalve parts is to subj'ect them to continuous use in an engine runningat a high speed. lit is generally considered thata valve which willstand a test of one hundred hours duration without failin is unusuallygood. In the tests ofthe Va ves Application filed August 18, 1023.Serial;- No. 658,040. I

' made of the alloy explained above an engine was run for threehundredhours continuously, and when the valves were removed they werefound to be in excellent condition.

Their surfaces did notshow any fire cracks or any signs of leakage. i

While the alloy provided according to this invention is peculiarlysuitable for internal combustion engine valves, valve seats and valvesleeves, it is also well suited for the manufacture of other hot worlrarticles, such as forging dies and dies for casting aluminum.

In the practice of the invention it will be understood that molybdenummay be used as an equivalent for tungsten.

I claim as my invention: 0

1. A steel alloy containing chiefly iron, and from about 2.0 to 7.0%tungsten, .2 to 5.0% cobalt, 2.0 to 8.0% chromium, and .2 to 1.5%carbon, the alloy being free from any additional element which wouldappreciably alter its high resistance to wear and to the development offire cracks when used under high temperature service conditions.

2. A. steel alloyconsisting of from about 2.0 to 7.0% tungsten, .2 to5.0% cobalt, 2.0 to 8.0% chromium, silicon not more than about 3.0%, and.2 to 1.5% carbon, and the remainder iron except for impurities.

3. A steel alloy containing chiefly iron, and about 6.0% tungsten, 5%cobalt, 7.0% chromium, and .45% carbon, the alloy being free from anyadditional element which would appreciably alter its resistance to wearand to the development of fire cracks when used under high temperatureservice conditions.

t. A. steel alloy consisting of about 6.0% tungsten, .5% cobalt, 7.0%chromium, 0.8% silicon, and .45% carbon, and the remainder iron exceptfor impurities.

lin testimony whereof, ll sign my name.

' DAVID J. GILES.

Witness:

G. G. TRILL.

